Abstract
Collections of diatrypaceous taxa from mangroves in southern Thailand yielded two novel species from intertidal habitats. Maximum parsimony, maximum likelihood and Bayesian analyses of combined ITS and beta-TUB sequence data, showed their placement in a well-separated lineage in Diatrypaceae (Xylariales). We therefore introduce a novel genus, Halodiatrype to accommodate the new species, H. salinicola and H. avicenniae. Cryptosphaeria mangrovei is morphologically similar to this genus, and thus it is synonymized as Halodiatrype mangrovei. Morphological descriptions, Fig.s. and molecular data are provided for the new taxa. Our studies show that the molecular data for Diatrypaceae is highly confused with species of the same genera scattered across the tree. The family therefore needs a detailed monograph with molecular data and multigene analyses with so far unpublished genes.